Conventionally, when a sheet supply cassette is installed to an image forming apparatus main body in such a image forming apparatus, a user pushes the sheet supply cassette in the apparatus to install the sheet supply cassette at a predetermined position in the image forming apparatus main body (e.g. see JP Laid-Open Patent Application No. 2003-276868, page 4, FIG. 6).
However, when the sheet supply cassette is installed to the image forming apparatus described above, force of the user to push the sheet supply cassette is insufficient and the user cannot install the sheet supply cassette securely.